Cycling has a relatively flat learning curve if you already know how to ride a bike. As you progress and want to improve further, though, you will start benefiting from having your ride’s metrics. Those numbers will help you take your workouts to the next level and keep your progress on track even without a coach. Still, to get your training numbers you need sensors, and knowing how to place the cadence and speed sensors on your bike is an essential piece of knowledge.
In this article we will discuss two very important factors regarding this topic:
- Where to place the sensors around your bike
- How to do that
If you’re also on the market looking for a good bike speedometer, make sure you check out my full Guide on that topic!
Where to mount the sensors
Let’s start with the cadence (RPM) sensor. There are three possible ways of you installing this sensor:
- It can be attached to the crank arm of your bike with a double-sided table. That is typically the easiest option although it isn’t as securely put as the next method
- Another option you can choose is using a mount with zip ties on the same spot of your crank arm. You can also get a sensor that comes with a base that has special bands to keep it in place.
- The last option is normally what most beginners go for. You place the sensor on its platform and then attach it to your shoe. It isn’t a very safe way of attaching this particular sensor and also not as accurate as having it on the crank arm.
Pro Tip: when mounting the RPM sensor, make sure you attach it either perpendicular or exactly parallel to the crank arm. It should also be on the inside of your non-drive crank arm. Putting it on the outside or onto the drive-side crank arm might cause some interference and it can fall off. The positioning doesn’t matter as much when you are attaching it to your cycling shoes.
Before we move forward, let’s quickly recap how most speed sensors work. They consist of two parts – one magnet (typically attached to the spokes) and a sensor that is put on the chain stay. The sensor will detect the magnet every time their locations meet. In other words, for every rotation, the magnet will pass only once across the sensor, giving it the information that 1 rotation is complete. By the number of rotations per a set period of time, the sensor can determine your approximate speed.
That being said, these sensors are most commonly located on your chain stay, spokes, or center of the wheel.
If you want to learn how to get faster on your bike, click here! Now, let’s move to the actual installation process.
Mounting your cadence and speed sensors
Cadence sensors are usually located around the speed sensors if you decide to place both of them in the back. They also consist of two parts – one magnet and one sensor that receives and transmits the signal. To install them, you need to zip-tie the sensor to the crank. Some sensors come with platforms to help you align them better since they do need to be in perfect alignment both with the crank and with the sensor. The details about the specific alignment the sensor needs are typically pointed out in the user manual. Once you do that, it is time to put the sensor on. Putting it on the spoke that has the speed sensor is the easiest way, even though some advanced cyclists argue that you have to put it opposite of that sensor to keep the tire more or less balanced.
Placing your speed sensor is a bit more tricky. There isn’t a set-in-stone option for setting them as they are all very different from one another. Some Garmin sensors are placed on the wheel hub while others have the more typical approach of being mounted at the chain stay. The speed sensors are attached to the chain stay with cable ties. These sensors typically have a smaller part (actual sensor) and a bigger part that transmits the signal to the main cycling computer. Modern sensors may also consist of one part only that handles all the work.
There are even speed sensors which double as cadence sensors and collect both of these metrics when you go out for a ride.
The good thing about speed sensors is that they always come with a way of strapping them to certain parts of your bike. Unlike cadence sensors, they don’t always have platforms and they are almost never secured with only double-sided tape.
While most people will rely on their cycling computers and speed sensors for their workout metrics, others prefer going the digital way by installing a good cycling app that tracks most of the metrics automatically through the sensors on your mobile device. Even better, some apps even work with most of the sensors your bike already has!
Frequently Asked Questions
How Do I install a Garmin speed sensor?
Newer Garmin speed sensors are among the easiest to install since they only consist of one element. You attach them to the center part of your bike’s wheel. It doesn’t matter if that part is symmetrical or not, the signal will always be accurate and these sensors are calibrated to work with all sorts of wheel shapes and sizes.
Do speed and cadence sensors work through Bluetooth?
While some sensors use Bluetooth for their signal transferring, the majority of speed and cadence sensors use ATN+. That is a protocol similar to Bluetooth that works across all training devices and other GPS and navigation tools. While ATN+ works really fast and at a better distance, Bluetooth does improve the practicality of your sensors as it allows them to work with your mobile phone and potentially with a third-party cycling app.
Knowing how to place cadence and speed sensors on your bike is going to be one of the first things you need to learn when you get on with cycling. Even if you move on from actual physical sensors to higher-end computers that mostly use GPS for that data, there will still be a high demand for analog data-collecting sensors which (for now) have a slight advantage in accuracy and durability. On top of that, no device can ever tell you your true cadence no matter the fancy calculations it is performing.